People with diabetes often develop clogged arteries that cause heart disease, and new research at Washington University School of Medicine in St. Louis suggests that low vitamin D levels are to blame.

In a study published Nov. 9 in the Journal of Biological Chemistry, the researchers report that blood vessels are less like to clog in people with diabetes who get adequate vitamin D. But in patients with insufficient vitamin D, immune cells bind to blood vessels near the heart, then trap cholesterol to block those blood vessels.